In a communications transmitter, information may be modulated onto orthogonal signals known as in-phase (I) and quadrature (Q) carriers to form I and Q channels. At a receiver, the transmitted I and Q channels may be demodulated to recover the information of interest. Accurate transmission and reception of information requires that the I and Q channels remain orthogonal to each other over the communications link.
In practice, mismatch may arise between the I and Q channels at the transmitter, over the communications link, or at the receiver, e.g., mismatch between I and Q downconversion paths in the receiver, and/or other sources. Such mismatch introduces correlation between the I and Q channels, causing information from the I channel to “bleed” into the Q channel, and vice versa. This leads to corruption of the information signals.
It would be desirable to provide techniques for estimating the I-Q mismatch at a receiver, and applying techniques to adjust the signals received in the I and Q channels to compensate for such I-Q mismatch. It would be further desirable to allow for flexible implementation of such techniques by partitioning the operations of estimating the mismatch and adjusting for the mismatch.